The problem of predicting the turbulent supersonic base pressure in axisymmetric flow is treated by an extension of a method of solution to the two-dimensional problem given in Ref. 1. The solution consists principally in tracing the boundary-layer development from upstream of the base to downstream of the recompression region for a given base pressure. A unique solution is obtained by specifying the shape of the rehabilitated boundary-layer velocity profile.

A comparison with experiment in the case of the step-down cylinder problem (the sting-support problem) yields some very favourable results. It is pointed out that, while it has not been found possible to obtain a solution to the problem of a vanishingly small sting, the base pressure does not vary appreciably while the sting is decreased from about 0-3 of the base diameter down to zero. It would appear that the present analysis is capable of giving accurate results down to sting/diameter ratios of the order of 0·3.

The intake is conceived as a device that generates a shock system and a subsonic patch within a supersonic field. The object of the paper is to obtain a qualitative description of this flow structure. The analytical procedure is a simple but fairly powerful mapping technique. Several examples are discussed and these show how the flow on the intake alters under the influence of gradually changing boundary conditions.

An attempt has been made to determine the natural frequency of fundamental flexural mode of a cantilever beam with uniform taper by the Galerkin method. The method suggested considerably reduces the calculations as compared with the other methods available and the results are checked with the correction factors derived by Martin.

Certain three-dimensional surfaces studied by Townend have the property that at every streamwise section a supersonic air stream is compressed isentropically in the form of a reversed Prandtl-Meyer flow. If all the compressions are centred on points lying on one straight line the flow is conical. Such a surface may be of use as an engine intake. In this paper an approximate boundary-layer calculation for such a surface is made for laminar flow with zero heat transfer in the conical case. It is found that under certain circumstances a useful amount of compression can be obtained before separation occurs (a pressure ratio of 6, for instance, for an initial Mach number of 10). Limiting streamlines are drawn and displacement thickness calculated for a typical case, and the Mach number at separation is determined for a range of initial Mach numbers and angles of sweep. Instability due to sweep is considered.

A study of the effect of linear damping on flutter speed is described. The energy exchange at flutter is considered in each degree of freedom of a general n-degrees-of-freedom system and an energy compatibility equation is formed. An analytical discussion of binary systems, based on the energy compatibility equation, is then presented.

From an investigation of published experimental results, it appears that three types of propagating stall cells occur on isolated blade rows. On stationary blade rows, and rotating rows which have the highest blade incidence at the tip, the speed of propagation seems to depend on a parameter based on the blade section near the leading edge, and in some experiments marked changes in this speed have been observed to coincide with changes in the form of stall on the individual blades. For rotating rows with the highest incidence at root or mid-section the speed of stall propagation lies within a fairly limited range and shows no dependence on the blade geometry. When the incidence is increased well beyond that at which stall first occurs, the stall cell pattern on most rotating rows changes from multiple cells to one or two of very large amplitude, with a marked change in speed of propagation.

Donnell type equilibrium and stability equations are derived for stiffened thin conical shells. The stiffeners are considered closely spaced and are therefore assumed to be “distributed” over the whole surface of the shell. In the proposed theory the stiffeners and their spacing may vary in any prescribed manner, but here only equal and equally spaced stiffeners are dealt with. The force- and moment-strain relations of the combined stiffener-sheet cross section are determined by the assumption of identical normal strains at the contact surface of stiffener and sheet.

The stability equations are solved for general instability under hydrostatic pressure by the method of virtual displacements. The solution used earlier for unstiffened conical shells, which satisfies some of the boundary conditions of simple supports only approximately, is again applied here. The effect of this incomplete compliance with boundary conditions is shown to be negligible by consideration of “boundary work”. The solution proposed for stiffened conical shells involves the concepts of “correcting coefficients” and minimisation of corresponding “error loads”.

Typical examples are analysed and the effect of eccentricity of stiffeners is investigated. Simplified approximate formulae for the critical pressure of frame-stiffened conical shells are also proposed.